WikiLeaks founder will ask permission to appeal against high court ruling that he must face sex crime charges in Sweden.

The founder of WikiLeaks, Julian Assange, is to apply for a supreme court hearing to appeal against extradition to Sweden to face sex crime allegations.

His solicitor, Gareth Peirce, confirmed he will ask senior judges in London on 5 December to certify that his case should be considered by the highest court in the land. He must establish that his case raises “a question of law of general public importance”.

Assange, 40, lost a high court battle against removal on 2 November but has announced he wants to fight on against a European arrest warrant that has been outstanding since last December.

A supreme court hearing would be the third stage of the 40-year old Australian’s appeal against extradition to face allegations of rape, sexual molestation and unlawful coercion by two women he met on a visit to Stockholm in August 2010.

Assange’s decision means a verdict on whether he should be extradited could be delayed until as late as next summer, legal observers said.